Acidic oleo-acrylic resins and processes for preparing same

ABSTRACT

Disclosed are acidic resins formed by reacting I. at least one poly-unsaturated monocarboxylic fatty acid containing 9 to 20 carbon atoms and more than one olefinic double bond (C C), or an ester of said acid with a polyvalent alcohol or a mixture of said acids and esters; and II. an Beta -unsaturated monocarboxylic acid of the formula:   WHEREIN X and Y are independently selected from the group consisting of hydrogen and alkyl groups having from 1 to 3 carbon atoms and Z is hydrogen or methyl group. These resins, which are useful in the production of paints and varnishes are of an acidic nature and contain component (II) in the combined state, in an amount ranging from 5 to 25 percent by weight.

SR1 3,890.2 United States Patent 1 1 j Montesissa et a1.

ACIDIC OLEO-ACRYLIC RESINS AND PROCESSES FOR PREPARING SAME Inventors: Giorgio Montesissa; Giancarlo Del Signor-e, both of Piacenza, Italy Assignee: Duco S.p.A., Trieste, Italy Filed: Apr. 8, 1974 Appl. No.3 456,950

us. (:1. 260/23 11; 106/14; 106/15 AK 106/17; 106/18; 260/23 P; 260/23 AR; 260/405 Int. Cl. C08f 19/14 Field of Search 260/23 R, 23 AR, 405, 23 P,

v 106/14, 15 AF References Cited FOREIGN PATENTS-OR APPLICATIONS 6/1966v United Kingdom 10/1966 United Kingdom Primary Examiner-Melvyn I. Marquis Assistant Examiner-Parker, William E. Attorney, Agent, or FirmI-lubbell, Cohen, and Stieffel I ABSTRACT Disclosed are acidic resins formed by reacting v 1 June 17, 1975 l. at least one poly-unsaturated monocarboxylic fatty acid containing 9 to 20 carbon atoms and 1 more than one olefinic double bond (C=C or an ester of said acid with a polyvalent alcohol or a mixture of said acids and esters; and

' II. an a, B-unsaturated monocarboxylic acid of the.

formula:

14-;Claims, No Drawings 1 2 ACIDIC CLEO-ACRYLIC RESINS AND As a matter of fact, the above mentioned reaction PROCESSES FOR PREPARING SAME cannot be carried out with all a,B-unsaturated acids.

, For example, by reacting a mixture consisting of an un- CROSS if f g ggi gg saturated oil (or an unsaturated fatty acid obtained 5 from such oil) and acrylic acid at 260C. one obtains, None. I in addition to an acidic product that is similar in some .respects to the product obtainable by using fumaric BACKGROUND OF THE INVENTION acid as the a,B-unsaturated acid, large amounts of l. Field of the Invention acrylic acid homopolymer, even when operating in the The present invention relates to acidic resins having presence of large amounts of polymerization inhibitors. particular properties which render them useful in the The presence ofthis homopolymer is evidenced by preproduction of resins for paints and varnishes. cipitation thereof with an excess of benzine.

More particularly, the invention relates to acidic The presence of this polyacrylic acid renders the oleoacrylic resins based on product cloudy and non-homogeneous. Moreover, I. at least one poly-unsaturated monocarboxylic fatty l5 films obtained from such product can be air driedjonly acid containing 9 to carbon atoms and more with difficulty, they are opaque and scarcely waterthan one olefinic double bond, or an ester of such resistant. After removal of the polyacrylic acid, the re acid with a polyvalent alcohol or mixtures of said sidual product exhibits an acidity and viscosity only acids and esters; and slightly exceeding those of the starting polyan a,B-unsaturated monocarboxylic acid of the 20 unsaturated fatty acids. If the reaction is conducted at formula: a higher temperature with-a view toward obtaining thejpr' sence.ofi dine"ors ilphur,Einal-l ;;B jtishgati- -with res ect-t6"m one'nt tI.) it is pessi' ble i em NO. 1,039,787 describes aqueous emlilSiOtiS ititnpris Y I i products with a higher viscosity and acidity, the homopolymerization of acrylic acid prevails over the other reactions.

, 2s SUMMARY OF THE INVENTION The present invention provides anew class of acidic Y 4 z I n l L resins hereinafter sometimes referred to as oleoacrylic resins, and processes for preparing same. wherein X and Y are independently selected from These resins are the product of a reaction between the group consisting of hydrogen and alkyl l. at least one poly-unsaturated monocarb oxylic fatty groups having from 1 to 3 carbon atoms, and Z acid containing 9 to 20 carbon atoms and more is hydrogen or methyl group, and wherein comthan one olefinic double bond (C=C) or an ester ponent (II) is present in the combined state in an of said acid with a polyvalent alcohol or a mixture amount ranging from 5 to 25 percent by weight of said acids and esters; and I of the total weight. The invention also relates to ll. an a,B-unsaturated monocarboxylic'acid of the processes for preparing such resins. formula:

2. Description of the Prior Art Various adducts of acrylic acid (acrylic acid esters) with poly-unsaturated fatty acids are known from the Q 7 k literature. Thus, for example, U.S. Pat. No, 2,452,029 discloses oily monomeric addition compounds of -l L I t mole of anacrylic ,ester.with l mole of a long-chain I I poly-unsaturatedfatty acid having conjugated double 3 bonds, obtained by reacting said components at a temt 'perature between 80 and 155C. According to English wherein X and Y are independently selected from Pat. Nos. l,032,363 and 1,046,207, dior tri-basic the group consisting of hydrogen and' alkyl acids are prepared by heating, in the range of to groups having from l to 3 carbon atoms, and Z is hydrogen or methyl group.

- 250C, (Diels-Alder reaction) mixtures of poly- These resins are of an acidic nature and contain comunsaturated fatty acids (or esters thereof) and a dieno 5O phile such as maleic acid, maleic acid anhydride. acry ponent (ll), in the combined state, in an amount rang lonitrile, acrylic acid, methyl acrylate and acrolein. in ing from 5" to 25 percent b'y'weig'ht.

ing, besides other substances, a saltleg, ammonium; j l unsaturate d mo'nocarboxy la ca rboxylic aliphatic c fi-uhsaturated acid, such asfil ,,wait-payvalefifinbdiipi pr ixtuire fdf sjaidflaeids cl inaric acid, with an unsaturated'oil'fs'iich as t'r'i'glycer- 'est'ersihowever'; if-a single ides of unsaturated fatty acids, at 240-2 60C. I must contain at least two olefinic double bonds. and

According to the examples of thisBriti'shpatent; the

- t ry .i rii=. i; in i salt) of an acidic resinous productpbtainedby reacting from Q'to 20 carbon atoms, or a mixture of their esters preferably at'leastone pair of-conjugated olefinic donate.

fumaric acid is admixed with the unsaturated oil and ble bonds. then brought to the reaction temperature. Of course, conjugated pairs of double bonds, in addi- From this patent it is known that, in order 'to carry tion to isolated double bonds may be present in the out the reaction, it is possible to employ, besides fupoly-unsaturated acids or esters employed. In practice,

maric acid which is the preferred a,B-unsaturated acid, and for economic reasons, it is preferable to use as other acids, such as maleic acid, crotonic acid, acrylic component (1), a mixture of monocarboxylic fatty acid or sorbic acid. acids (or esters thereof) which, in addition to the polyunsaturated acids (or esters) having at least two olefinic double bonds, may also contain mono-unsaturated and/or saturated acids, but preferably in amounts not exceeding 50 percent by weight of the total mixture. Moreover. it is to be taken into account that pairs of isolated double bonds, if present in the chains of the fatty acids (or their esters), of component (I) may isomerize under the reaction conditions, thus giving rise to conjugated double bonds.

As examples of component (I) which may be used in the invention, there are included: dehydrated fatty acids of castor oil, fatty acids of linseed oil, fatty acids of safflower oil, fatty acids of soya bean oil, fatty acids of tall oil and the so-called isomerginic acids," i.e. poly-unsaturated fatty acids having at least one pair of conjugated double bonds, and obtained from fatty acids having isolated double bonds by isomerization (shift of double bonds)'catalyzed by alkalis. Thus, for example. from linoleic acid there can be obtained a mixture of two fatty acids having conjugated double bonds:

' Analogous'ly, it is possible to isomerize polyenic fatty acids having a higher molecular weight or esters thereof with polyvalent alcohols such as glycerol, pentaerythritol, trimethylol-ethane, trimethylol-propane.

As component (II), the preferred acids are acrylic acid or methacrylic acid.

It has now been surprisingly found that it is possible to prepare acidic resinous products which are substantially free from significant amounts of homopolymerized acrylic acid by reacting (l) poly-unsaturated fatty acids (or esters thereof with polyvalent alcohols) with (ll) G,Bunsatura'ted acids, such as for example acrylic acid, at a temperature ranging from 250 to 300C, by gradually admixing the a,B-unsaturated anhydrous acid to the poly-unsaturated fatty acid or to a mixture of poly-unsaturated fatty acids (or esters thereof), heated to the reaction temperature, in amounts such that in the reaction mixture during the course of the reaction, the ratio by weight of free (uncombined) a,B-unsaturated acid to combined a,B-unv saturated ac idis in the range of from 0.1 ml, and ispreferablyconstant within allowance limits not exceedmg: 0.05, in order to obtain as uniform a final product as possible. 1 r

According to the invention, the process for preparing. the acidic or oleo-acrylic resins of the invention is as follows:

I solvent capable of forming an azeotrope with water,

l such as toluene or xylene. The mass is heated to a temperature between 180 and 220C under reflux conditions, in order to remove any water contained in the polyunsaturated acids (or esters) by azeotropically distilling same off. Succes'sively the temperature is raised to the selected value 3C) in therange of from 250 to 300C, and the a,B-unsaturated acid, e.g. glacial acrylic acid, is gradually introduced under stirring into the reactor, generally, by'means of a feeding pump. The optimum flow rate of the acid' is fixed tentatively or by separate tests carried out under analogous conditions. Successively, periodic checkings of the amount of 0:,[3-unsaturated acid present in the free state in the reaction mixture are carried out by analyzing weighed samples of the reaction mixture withdrawn from the reactor and, if necessary, the required concentration of the acid in the reaction mixture is restored by varying the feed rate.

The reaction is conducted for a time varying from 10 to 30 hours, while carefully regulating the temperature at the top of the cooling column to a value of 50-60C which is necessary to recondense the afi unsaturated acid in the reactor.

The reaction may be effected either in the presence or in the absence of an inert gas (nitrogen) at atmospheric pressure or, at the most, at a pressure of 2 atmospheres. The course of the reaction is monitored by The oleo-acrylic resins according to the invention generally have an acid "valuebetween 0 and 300, ,a viscosity between the values P and Z on the Gardner- Holdt scale, a content of combined a,B-unsaturated acid ranging from 5 to 25 percent by weight, and are substantially free from significant amounts of homdpolymerized a,B-unsaturated acid.

Films obtained from the resins of the invention easily dry in air, they are glossy and water-resistant.

For the sake of safety, it is preferable to conduct the reaction {between the poly-unsaturated fattyacid aha the'dfi-unsatufat'ed acidi'n the presence of apolymer iza'tion inhibito rfsuc h as hy'd roquinone or sii'it'able de- 'rivatives thereof, which inhibitorsdo not adverselyafbased or water-based resins. The presence of double bonds that are polymerizable by oxidation permits'the use of these resins as resins capable of air-drying in admixture with other solvent-based or water-based resins.

' ln addition, the acidic resins of this invention may be used as intermediates for the preparation of resins, in

particular, of those resins that are soluble or dispersible' .in water.

he high percentage ofcarboxyl g i oiupslajnd thegreat ,react ivity of the resins of this invention render them,

useful ascross-linlting resins .when they are heattreated in a furnace in admixture with other solvent-' invention. withour however being a limitation thereof.

EXAMPLE I L800 g of a mixture of castor-oil dehydrated fatty acids, having an acid value ranging from l75 to I80,

along with l.4 g of hydroquinone and 6 g of xylene.

were introduced into a 6 liter reactor provided with a stirrer. a heating jacket and a reflux condenser. The mixture was heated to a temperature of about 200C, and heating was continued until all traces of thewater contained in the mixture were removed. The temperature was then raised to 260C (:L 3C) and glacial acrylic acid was fed in at an initial flow rate of 20 g/h, while simultaneously feeding the reactor with a slight continuous flow of nitrogen. The temperature at the top of the reflux column was 60C (i 3C).

From an analysis of samples drawn from the reaction mixture l5 to 25 minutes after starting the reaction. it was observed that about 75 percent of the introduced acrylic acid reacted. while the remaining 25 percent remained in the free state in the reactor. 'l'his corresponds to a weight ratio of free acrylic acid to combined acrylic acid equal to about 0.3. Acrylic acid was further added at a flow rate of about g/h. with the flow rate being suitably varied during the course of the reaction according to the results of analyses of samplesof the reaction mixture periodically drawn. in order to maintain the ratio of free to combined acrylic acid in the reactor at a constant of 0.3 $0.05 for the entire reaction period.

20 hours after the commencement ofv the reaction,

during which time abo ut360 g'ofacrylic acid has'bc enfed. the reaction product. when freed from the unreacted acrylic acid, exhibited a viscosity, measured at C in the undiluted product. between the values Z and 2;, of the Gardner-Holdt scale. and an acid value of about 255. At this point. the feeding of acrylic acid was stopped. the reflux column was no longer cooled and the mixture was brought to a temperature ranging 'from 60 to 30C under vacuum. these conditions being maintained until all of the unreacted acrylic acid had been extracted by distillation. About 90 g of acrylic acid were thereby obtained. The reaction product amounted to about 2.080 g and contained about l3 percent by weight of combined acrylic acid.

A sample of one part or theobtained product was mixed with 7 parts of benzine whereby a limpid-solution was obtained. indicating the absence of any significant amounts ofpolyacrylic acid in the reaction product.

EXAMPLE 2 The same reactor as utilized in Example I was charged with 2.400 g of a mixture of poly-unsaturated monocarboxylic fatty acids. the so-called isomerginic acids" (isomcrginic acids SY. produced by Hamburger operating and monitoring techniques described in Example l. the conditions were so adjusted as to obtain a weight ratio of free methacrylic acid to combined methacrylic acid equal to 0.5 (t 0.05).

After 20 hours. during which 580 g of methacrylic acid had been fed. the reaction was stopped and about I95 g of unrcactcd mcthacrylic acid were obtained. The reaction product amounted to about 2.790 g; had a Gardner-Holdt viscosity value, at 25C, between Z and Z an acid value of about 270 and a combined methacrylic acid content equal to about l3.8 percent by weight. The admixing of a sample of the product with benzine in a 1:7 ratio revealed the presence of only traces of polymethacrylic acid.

EXAMPLE 3 The reactor used in Example l was charged with 2,400 g of safflower oil along with 9.5 g of xylene. This mixture was heated under stirring to 2002l0C until all traces of the water contained therein were removed. The mixture was then brought to a temperature of 255C (3 3C), whereupon acrylic acid was gradually introduced into the reactor, so as to achieve in the reactor, a weight ratio of free acrylic acid to combined acrylic acid equal to 0.2 (i 0.05). After 20 hours, during which 378 g of acrylic acid had been fed. the reac- A reactor as described in Example l was charged with 2.500g of a mixture. of 45 percent by weight of conjugated linseed'oil'and 55 percent by weight of a mixture of castor oil dehydrated fatty acids having an acid value of l-l80. along with 9 g of toluene After removing all traces of the water in the mixture by heating to about 200C. the mixture was broughtto a tempcrature of 280C (t 3C) and acrylic acid was fed in. taking care that in the reactor a weight ratio of free acrylic acid to combined acrylic acid equal to 0.9 l (i 0.05) was maintained.

The reaction was conducted for 20 hours. during which 646 g-of acrylic acid were fed inQafter which the reaction was stopped and about 306 g .of unreacted acrylic acid were extracted from the mixtureby distillation at 6080(-." under vacuum. I

The reaction product amounted to about 2.840 g:

had'a Gardncr-Holdt viscosity. measured at 25C in. the undiluted product. between the values Z and Z... an 9 acid value of about I86 and a combinetl acryli'c acid content of about l2 percent by weight.

A l:7 mixture ofthc product with benzine revealed. that only traces of polyacrylic acid are presentin the product.

EXAM Pl.E 5

7 00 g ofa mixture of safflower oil fattyacids having an acid value of about l90 along with 8 g of toluene were introduced into a reactor ast'iescribcd in Example After heating at 2002 lC for about 0.5 hour. the temperature of the mixture was increased to 255C (1- 3C) and glacial acrylic acid was added at an initial flow rate of 32 g/h, while simultaneously feeding the reactor with a nitrogen flow.

The temperature at the top of the reflux column was about 50C. Analysis of samples of the reaction mixture drawn during the time interval of l5-25 minutes after commencement of the reaction revealed that 58 percent of the introduced acrylic acid reacted. while the remaining 42 percent remained -in the reactor in the free state. Thus. the ratio of free acrylic acid to combined acrylic acid in the reaction mixture was about 0.7. The feeding of acrylic acid was continued. taking care, on the basis of analyses of samples of the mixture drawn at regular time intervals, to suitably vary the feed rate so as to maintain the ratio of free to combined acrylic acid constant at about 0.7 i005 for the entire reaction period.

The reaction was stopped after hours, during which time about 650 g of acrylic acid had been added. Approximately 268 g of unrcacted acrylic acid were removed from the reaction mixture by distillation under vacuum at 60-80C. The reaction product amounted to about 2,582 g; had a combined acrylic acid content of about l4.8 percent, an acid value of 275-278 and a Gardner-Holdt viscosity value at C between 0 and S.

Only traces of polyacrylic acid-were'present in the reaction product.

COMPARATIVE EXAMPLE This example is designed to prove that, when in the reaction mixture the weight ratio of free a,B-unsaturated acid to combined a,B-unsaturated acid is outside the range of from 0.1 to l, the products obtained thereby do not possess satisfactory characteristics and are thus unusable.

The reaction was conducted by maintaining in the reaction mixture a weight ratio-of free a,B-unsaturated acrylic acid to combined acrylic acid equal tol.2 (i g A sample of the reaction mixture was withdrawn from the reactor from time to time in order to determine the abovesaid ratio in the following way. From the withdrawn sample the free acrylicacid was removed by distillation under vacuum at 60-70C; from the residue of the sample, the polyacrylic acid was removed by precipitation with benzine and, finally, the amount of combined acrylic acid was determined by acidimctry on the thus obtained sample. The analyses of the sam- I ples withdrawn during a minute period from the umc at which acrylic acid feeding began, revealed that he weight ratio of free acrylic acid to combined acrylic acid was equal to about l.2. At the same time, it was PHsible to visually observe the formation of polyacrylic acid on the reactor walls and in the reaction mass as well.

The reaction was stopped after 20 hours of feeding in the acrylic acid. i.e. when about 792 g of acrylic acid at a flow rate of about 40 g/h had already been introduced. By subjecting the reaction mixture to distillation under vacuum at 60-80C. about 234 g of free acrylic 5. acid were obtained; about 360 g of polyacrylic acid were precipitated in the residuc'by adding benzine and. after distillation ofthe benzine, about 2.197 g ofa reac-' tion product having an acid value of about 231 and a Gardner-Holdt viscosity value, measured at 25C in the undiluted product, between J and K were obtained. The combined acrylic acid contained in the reaction product amounted to about 9 percent.

Films prepared from this product comprising polyacrylic acid can be air dried only with difficulty, they are opaque and only scarcely water-resistant.

The product, after being freed from the polyacrylic,

acid, exhibits characteristics substantially similar to those of the starting fatty acids, and said product is, by consequence, unemployable either as a resin or as an intermediate for the preparation of water-based resins having a more complex molecular structure.

It was assumed that the exceptional characteristics of the resins according'to the invention are attributable at least in part to the formation of addition products of the a,B-unsaturated acid with oligomers (dimers and trimers) of the poly-unsaturated acids or esters.-

This assumption is borne out by the following test conducted for analytical purposes. I

EXAMPLE 6 A 6liter reactor provided with stirrer, heating jacket and reflux condenser was charged with 1.800 g'of-a mixture of castor oil dehydrated fatty acids having an acid value of 175-180, along with 6 g of xylene 'The mixture was heated to 200C until all traces of'water had been removed. The temperature was then increased to 260C 3C) and maintained thereat for g 20 hours. Samples taken from the reaction mixture and mained constant, while the viscosity of the product gradually increased. until reaching, after 20 hours, a value between G and H on the Gardner-Holdt scale. This product was subjected to gas-chromatographic analysis, as was a commercial dimeric product (DlMAC produced by Victor Wolf Ltd.) for comparative purposes. l

The comparative gas-chromatographic 'analyses showed that the product obtained by heating to260C consisted of about 95 percent of dimers of the polyunsaturated fatty acids. This product, when reacted l with acrylic acid according to the procedures described in Example l. resulted in another product 'having an acid value of about 222 (corresponding to about 8 percent of combined acrylic acid) and a Gardner-Hold viscosity value rangingfrom Z to Z W When this procedure is repeated employingthe com mercial dimeric product (DlMAC of Victor Wolf Ltd no product was obtained from the reaction with acrylic acid. In fact. the acidity and viscosity of the mass remained constant all through the heating period.

Variations and modifications can. of course. be made' without departing from the spirit and scope of the invention.

Having thus described our invention. what we desire to secure by Letters Patent and hereby claim is:

subjected to-analysis, revealed that the acidity re 9 I. An acidic resin consisting essentially of the product obtained by reacting, at a temperature between about 250 and 300C,

l. at least one poly-unsaturated monocarboxylic fatty acid having from 9 to 20 carbon atoms and more i than one olefinic double bond or an ester of said acid with a polyvalent alcohol or a mixture of said acids and esters with I]. an a,B-unsaturated monocarboxylic acid of the wherein X and Y are independently selected from the group consisting of hydrogen and alkyl groups having from 1 to 3 carbon atoms, and Z is hydrogen or methyl group, the reaction being carried out by admixing the a,B-unsaturated monocarboxylic acid to component (I) in an amount such that in the reaction mixture, the weight ratio of free afi-unsaturated acid to combined a,B-unsaturated acid is between 0.1 and l; and wherein the a,B-unsaturated monocarboxylic acid constitutes between 5 and 25 percent by weight of the product, said product having an acid value ranging from 60 to 300, a viscosity value between -P and Z on-the Gardner-Holdt scale, and being substantially free of homopolymers of the a,B-unsaturated monocarboxylic acid.

2. An acidic resin according to claim 1, wherein the a,B-unsaturated acid is acrylic acid or methacrylic acid.

3. An acidic resin according to claim 1, wherein com- I ponent (l) is a mixture of castor oil dehydrated fatty acids.

. 4. An acidic resin accordingto claim 1, wherein component (l)' is soya bean oil;

5. An acidic resin accordi fatty acids of castor oil.

. 6. An acidic resin according to claim .1, wherein component (l) is amixture of soya bean-oil fatty acids.

ng to claim 1, wherein 'coniv ponent (l) is a mixture of safflower oil anddehydrated' 45V c I coon l z wherein X and Y are independently selected from the group consisting of hydrogen and alkyl groups having from 1 to 3 carbon atoms, and Z is hydrogen or methyl group at a temperature between about 250 and 300C and at a pressure ranging from about 1 to 2 atmospheres, said reaction being carried out by admixing the a,/3-unsaturated monocarboxylic acid to component (I) which has been heated to the reaction temperature, in an amount such that in the reaction mixture, the weight ratio of free a,B-unsaturated acid to combined a,B-unsaturated acid is be-.

tween 0 l andl. 9. A process according to claim 8, wherein compoacids. 1

10. A process according to claim 8, wherein component (l) is soya bean oil.

11. A process according to claim 8, wherein compofatty acids of castor oil.

12. A process according to claim 8, wherein compo- 'nem (i) is a-mixture of soya beanoil fatty acids. 13. A process according to claim 8, wherein component (l) is isomerginic acid. Q

nent (ll) is acrylic acid in a a: a a:

or methacrylic acid.

nent (I) is a mixture of castor oil dehydrated fatty nent (I) is a mixture of safflower oil and dehydrated V 14. A process according to claim 8, wherein compo- UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,890,259 Dated June 17, 1975 Inventor(s)GiOrgiO MONTESISSA and Giancarlo DEL SIGNORE It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below: O

Title page, left side, should have Priority Data, Italian Application 22725-A/73, April 9, 1973 O Title page, left side, under "Attorney, Agent, or Firm":

"Stieffel" should read Stiefel Q Column 5, line 37: "has" should read had Column 6, line 30: "2.715 g;" should read 2,715 g;

Column 6, line 59: "186" should read 168 Column 10, last line of claim 8: "01" should read O.l--.

Signed and Sealed this fourteenth D8) Of October 1975 [SEAL] Arrest:

. RUTH c. MASON c. MARSHALL DANN Arresting Officer Commissioner uj'Patents and Trademarks Q I. J 

1. AN ACIDIC RESIN CONSISTING ESSENTIALLY OF THE PRODUCT OBTAINED BY REACTING, AT A TEMPERATURE BETWEEN ABOUT 250* AND 300*C, I. AT LEAST ONE POLY-UNSATURATED MONOCARBOXYLIC FATTY ACID HAVING FROM 9 TO 20 CARBON ATOMS AND MORE THAN ONE OLEFINIC DOUBLE BOND OR AN ESTER OF SAID ACID WITH A POLYVALENT ALCOHOL OR A MIXTURE OF SAID ACIDS AND ESTERS WITH II, AN A,B-UNSATURATED MONOCARBOXYLIC ACID OF THE FORMULA:
 2. An acidic resin according to claim 1, wherein the Alpha , Beta -unsaturated acid is acrylic acid or methacrylic acid.
 3. An acidic resin according to claim 1, wherein component (I) is a mixture of castor oil dehydrated fatty acids.
 4. An acidic resin according to claim 1, wherein component (I) is soya bean oil.
 5. An acidic resin according to claim 1, wherein component (I) is a mixture of safflower oil and dehydrated fatty acids of castor oil.
 6. An acidic resin according to claim 1, wherein component (I) is a mixture of soya bean oil fatty acids.
 7. An acidic resin according to claim 1, wherein component (I) is isomerginic acid.
 8. A process for preparing an acidic resin according to claim 1, said process comprising reacting I. at least one poly-unsaturated monocarboxylic fatty acid having 9 to 20 carbon atoms and more than one olefinic double bond, or an ester of said acid with a polyvalent alcohol or a mixture of said acids and esters; and II. an Alpha , Beta -unsaturated monocarboxylic acid of the formula:
 9. A process according to claim 8, wherein component (I) is a mixture of castor oil dehydrated fatty acids.
 10. A process according to claim 8, wherein component (I) is soya bean oil.
 11. A process according to claim 8, wherein component (I) is a mixture of safflower oil and dehydrated fatty acids of castor oil.
 12. A process according to claim 8, wherein component (I) is a mixture of soya bean oil fatty acids.
 13. A process according to claim 8, wherein component (I) is isomerginic acid.
 14. A process according to claim 8, wherein component (II) is acrylic acid or methacrylic acid. 